What Is Blood Letting?

For most of human history, people believed that blood flow was a one-way thing. The discovery that blood flowed two ways–that there was a circulatory system–didn’t happen until the mid-1600s. And it took more than a century for that discovery to be formally adopted by most scientific institutions. Abdul goes back in history to help us understand the resistance to science in the present. He interviews Dr. Dhun Sethna, a cardiac anesthesiologist and author of “The Wine Dark Sea Within” about the discovery of the human circulatory system and it’s implications for our time.